Algae discoloration:a type of roof discoloration caused by algae build up on roof. Also called fungus growth
Asphalt shingle: a type of shingles that have a central core of cellulose fibers or fiberglass, coated with modified asphalt on both sides and topped with protective granules. Most asphalt shingles have a class A rating. Also called composition shingles.


Bundle: package of shingles. There are usually 3, 4 or 5 bundles per square.


Caulk: an item used to fill gaps in exterior siding and roofing; seals out drafts, moisture, and insects; and seals in warm or cool air. There are five types of caulk: elastomers, butyl rubber, acrylic latex, non-acrylic latex and oil-base
Chimney base flashing: a corrosion-resistant sheet metal installed at the base of a chimney to prevent leaks.
Class “A”: the highest fire resistant for roofing as per ASTM E-109. It indicates roofing materials that can withstand severe exposure to fire originating from outside sources
Class “B”: fire resistant rating that indicates roofing materials that can withstand moderate exposure to fire originating from outside sources
Class “C”: fire resistance rating that indicates roofing materials that can withstand light exposure to fire originating from outstide sources
Collar: pre-formed flange placed over a vent pipe to seal the roof around the vent pipe opening. Also called vent sleeve.
Counter flashing: a part of the flashing joined to the vertical surface as a way to prevent water leakage
Course: a row of shingles spread on the length of the roof.
Cutout: the open pieces of a strip shingle between the tabs


Dimensional shingles: a type of shingle that is textured, laminated or overlayed to produce a three-dimensional appearance. They are thicker than multi-tab shingles increasing its wind resistance and durability. They often lasts 30 to 50 years depending on the weather and installation. Also called architectural/three-dimensional/laminated/textured shingles.
Dormer window: a framed window unit that protrudes through the slanted roof
Downsprout: a pipe for draining water from roof gutters. Also called leader
Drip edge: a narrow strip of non-corrosive, non-staining, finishing material installed along the eaves and rakes to allow water run-off to drip clear of underlying construction. On eaves where gutters are present, this material is commonly called gutter apron.


Eaves: the horizontal, lower edge of a slanted roof.
Edging strips: boards nailed along eaves and rakes after cutting back existing wood shingles to provide secure edges for re-roofing with asphalt shingles.
Exposed nail method: application of roll roofing in which all nails are driven into the cemented, overlapping course of roofing, making them exposed to the weather.
Exposure: part of the shingle exposed to the weather.


Fascia: horizontal trim at the eaves that covers the rafter ends.
Felt: a flexible sheet that is saturated with asphalt and used as an underlayment, also called “tar paper”
Fiberglass mat: an asphalt roofing base material manufactured from glass fibers.


Gable: the upper portion of a sidewall that comes to a triangular point at the ridge of a sloping roof.
Gable roof: a type of roof containing sloping planes of the same pitch on each side of the ridge. A gable roof typically contains a gable at each end.
Gambrel roof: a type of roof containing two sloping planes of different pitch on each side of the ridge. The lower plane has a steeper slope than the upper. A gambrel roof usually contains a gable at each end, just like a standard gable roof.
Granules: ceramic-coated colored crushed rock that is applied to the exposed surface of asphalt roofing products.
Gutter: the trough that channels water from the eaves to the downspouts.


Hip: the inclined external angle formed by the intersection of two sloping roof planes. The hip runs from the ridge to the eaves.
Hip roof: A type of roof containing sloping planes of the same pitch on each of four sides. A hip roof contains no gables.
Hip shingles:Shingles used to cover the inclined external angle formed by the intersection of two sloping roof planes.
Horizontal siding: provides style and functionality. Available in various materials, colors, textures and designs.
Housewrap: material designed to allow moisture to escape and to prevent air from coming in.


Ice dam: Ice dams occur when snow melts near the ridgelines of warm roofs (roofs without adequate ventilation). As the water runs down the roof to the overhang, it cools and freezes. If the snow continues this melt and freeze process, an ice dam can form that can seep under the shingles, through the decking and into the house. This, of course, can cause serious roof leaks–even in freezing temperatures.

The best prevention to ice dams is a well-ventilated (cool) roof. Additional protection for your roof can be applied with an impermeable ice and water membrane. The membrane is installed on top of the decking, under the roofing material. Temporary prevention of ice dams can also be done through the use of electric cables along the eaves of the roof (where the dams usually form). However, new ice dams can form above the cables and still cause extensive damage. Another emergency solution to ice dams is to fill a sock or nylon with calcium chloride. Lay the stocking vertically across the ice dam. The calcium chloride will melt the ice and release the water so that it can drain outside, and not inside your roof.

Intake Ventilation: The part of a ventilation system used to draw fresh air in. Usually vents installed in the soffit or along the eaves of a building.


Laminated shingles: Strip shingles containing more than one layer of tabs to create extra thickness. Laminated shingles are also called three-dimensional shingles.
Lap: To cover the surface of one shingle or roll with another.
Life-cycle cost: The total lifetime cost of a roof. Calculated by adding maintenance costs to the installed price, then deducting the added value the roof provides when the home is resold.
Lookout: a horizontally positioned board used to brace the trusses of a roof


Mansard roof: A type of roof containing two sloping planes of different pitch on each of four sides. The lower plane has a much steeper pitch than the upper, often approaching vertical. Contains no gables.
Metal drip edge: A narrow strip of non-corrodible metal used at the rake and eave to facilitate water runoff.


New construction: Installing a roof system on new construction.
Non-prorated warranty: A warranty which provides full replacement costs for the item(s) covered during the full term of the warranty. In contrast, a prorated warranty merely reimburses a percentage of replacement costs, depending on the age of the roof.


Open valley: Method of valley construction in which shingles on both sides of the valley are trimmed along a chalk line snapped on each side of the valley. Shingles do not extend across the valley. Valley flashing is exposed.
Organic felt: An asphalt roofing base material manufactured from cellulose fibers.
Organic shingle: An asphalt shingle reinforced with organic material manufactured from cellulose fibers.
Overhang: That portion of the roof structure that extends beyond the exterior walls of a building.


Parapet: A low protective wall that extends above the roofline or balcony for support.
Pitch: Also known as “slope”, pitch is the measure of how “steep” a roof is. For example, if a roof is “4 in 12”, the roof rises 4 inches for every horizontal run of 12 inches. The pitch of the roof is a big factor in determining the kinds of materials that can be used and the longevity of the roof. Usually, a steeper roof (higher pitch) will last longer due to its better drainage capabilities.
Ply: The number of layers of roofing: i.e. one-ply, two-ply.


Rafter: the supporting framing member immediately beneath the deck, sloping from the ridge to the wall plate.
Rake: the inclined edge of a sloped roof over a wall from the eave to the ridge.
Release tape: a plastic or paper strip that is applied to the back of self-sealing shingles. This strip prevents the shingles from sticking together in the bundles, and need not be removed for application.
Roof-over: the installation of a new roof system over an existing system without removing an existing system.
Roof sheating(boards or plywood): the structural base of a roof. Also called the roof deck, or decking.
Re-roofing: installing a new roof system on a building that is not new.
Ridge: the uppermost, horizontal external angle formed by the intersection of two sloping roof planes.
Ridge beam: the top support beam between opposite slopes or sides of a roof.
Ridge shingles: shingles used to cover the horizontal external angle formed by the intersection of two sloping roof planes.
Rise: the vertical distance from the eaves line to the ridge.
Roll roofing: asphalt roofing products manufactured in roll form.
Roofing tape: an asphalt-saturated tape used with asphalt cements for flashing and patching asphalt roofing.
Roof truss: The framework that supports a roof
Run: the horizontal distance from the eaves to a point directly under the ridge. One half the span.


Self-sealing shingles: shingles containing factory-applied strips or spots a thermal sealing tab cement to firmly cement the shingles together automatically after they have been applied properly and exposed to warm sun temperatures. In warm seasons, the seal will be complete in a matter of days. In colder seasons, sealing time depends on the temperature and amount of direct sunlight hitting the shingles. Hand sealing with plastic cement should be done to ensure sealing in winter.
Self-sealing strip or spot: factory-applied adhesive that bonds shingle courses together when exposed to the heat of the sun after application. Also known as self-sealing cement.
Sheathing: exterior grade boards used as a roof deck material. “Step sheathing” is used alone or in combinations with solid sheathing for installation of tiles or shakes. Step sheathing allows air circulations under the tiles by using 1-by-6 or 2-by-6 boards that are evenly spaced so that air can move under the tiles or shakes.
Shed roof: a roof containing only one sloping plane. Has no hips, ridges, valleys or gables.
Shingle siding: a siding option typically manufactured from red cedar, which weathers to a silvery gray or medium brown, depending on local climate; and white cedar, which weathers to a silvery gray

Shingles: The outermost covering of a roof. Composition shingles are manufacured from materials “composed” of fiberglass, modified asphalt and mineral granules. Wood shingles and shakes (shakes are split rather than sawn) are made from western red cedar. Other roofing options include clay and concrete tiles, slate, metal, mineral roll roofing, and tar and gravel.
Slope: the degree of roof incline expressed as the ratio of the rise, in inches, to the run, in feet.
Soffit: the finished underside of the eaves.
Soil stack: a vent pipe that penetrates the roof.
Square: a unit of roof measure covering 100 square feet.
Starter strip: asphalt roofing applied at the eaves that provides protection by filling in the spaces under the cutouts and joints of the first course of shingles.
Steep slope application: method of installing asphalt shingles on roof slopes greater than 21 inches per foot.
Step flashing: flashing application method used where a vertical surface meets a sloping roof plane.


Tab: the exposed portion of strip shingles defined by cutouts.
Tar paper: See “Felt”
Tear off: removing an existing roof system.
Three-dimensional shingles: See laminated shingles or dimensional shingles.

Three-tab shingle: the most popular type of asphalt shingle usually 12″ x 36″ in size with three tabs.


UL: Underwriters Laboratories, Inc. An independent testing service for roofing materials
UL label: label displayed on packaging to indicate the level of fire and/or wind resistance of asphalt roofing.
Underlayment: a layer of saturated asphalt felt laid under most roofing materials as a secondary water barrier


Valley: the internal angle formed by the intersection of two sloping roof planes to provide water runoff.
Valley flashing: an additional water barrier, made from aluminum or galvanized steel, that is installed after the roof and valley have been covered with underlayment
Vent: any outlet for air that protrudes through the roof deck such as a pipe or stack for the purpose of added ventilation
Vent flashing: made from aluminum or galvanized steel, this additional water barrier is installed after the roof and valley have been covered with underlayment
Vent sleeve: see collar.
Vertical panel siding: Plain, patterned, or grooved panels of plywood or hardboard that provides style and functionality


Wall sheathing: the first covering of boards on the outside wall of a frame house
Wall stud: an upright piece of wood used to frame a house and support the walls of the structure
Water and Ice/Winterguard : waterproofing shingle underlayment that aims to protect the most vulnerable places in the roof against water penetration.